[FFmpeg-devel] [PATCH] avcodec/cbs_mpeg2: create a reference to the existing buffer when decomposing slice units

[Xiang, Haihao]

> Signed-off-by: James Almer <jamrial at gmail.com>
> ---
>  libavcodec/cbs_mpeg2.c | 9 ++-------
>  1 file changed, 2 insertions(+), 7 deletions(-)
> 
> diff --git a/libavcodec/cbs_mpeg2.c b/libavcodec/cbs_mpeg2.c
> index 989daf0a4d..8ca47061fe 100644
> --- a/libavcodec/cbs_mpeg2.c
> +++ b/libavcodec/cbs_mpeg2.c
> @@ -191,16 +191,11 @@ static int cbs_mpeg2_read_unit(CodedBitstreamContext
> *ctx,
>          len = unit->data_size;
>  
>          slice->data_size = len - pos / 8;
> -        slice->data_ref  = av_buffer_alloc(slice->data_size +
> -                                           AV_INPUT_BUFFER_PADDING_SIZE);
> +        slice->data_ref  = av_buffer_ref(unit->data_ref);

How about adding an assertion to check unit->data_ref against NULL?

>          if (!slice->data_ref)
>              return AVERROR(ENOMEM);
> -        slice->data = slice->data_ref->data;
> +        slice->data = unit->data + pos / 8;
>  
> -        memcpy(slice->data,
> -               unit->data + pos / 8, slice->data_size);
> -        memset(slice->data + slice->data_size, 0,
> -               AV_INPUT_BUFFER_PADDING_SIZE);
>          slice->data_bit_start = pos % 8;
>  
>      } else {